electromagnetic field

9 Articles

[Michael Karliner]’s Belshazzar, named for the Biblical character upon whose wall the writing appeared, is a unique light painting machine, that tracks an array of UV LEDs across a glow-in-the-dark background to paint transient dot-matrix letters in light. It was one of many cyberpunk-themed art pieces in Null Sector at the 2018 Electromagnetic Field hacker camp this summer.

The row of LEDs hangs down from a carriage that traverses a tubular rail, and is edged forward by means of a stepper motor driving a roller. This arrangement delivers the benefit that it can be scaled for displays of any length. The LEDs are driven from an Arduino via a Texas Instruments TLC5940 PWM driver ship.The result can be seen in the video below the break, and those who saw it at EMF may remember it tracing suitably dystopian phrases.

This summer’s Electromagnetic Field hacker camp in a field in western England gave many of the European side of our community their big fix of cool stuff for the year.

Some lucky individuals can spend the year as perpetual travelers, landing in a new country every week or so for the latest in the global round of camps. For the rest of us it is likely that there will be one main event each year that is the highlight, your annual fill of all that our global community has to offer. For many Europeans the main event was the biennial British event, Electromagnetic Field. From a modest start in 2012 this has rapidly become a major spectacle, one of the ones to include in your calendar, delivered both for our community and by our community.

David Mills is as a research scientist at the cutting edge of medical imaging. His work doesn’t involve the scanners you might find yourself being thrust into in a hospital should you be unfortunate enough to injure yourself. He’s working with a higher grade of equipment, he pushes the boundaries of the art with much smaller, very high resolution CT scanners for research at a university dental school.

He’s also a friend of Hackaday and we were excited for his talk on interesting uses for CT scanners at EMF Camp this summer. David takes us into that world with history of these tools, a few examples of teeth and bone scans, and then delves into some of the more unusual applications to which his very specialist equipment has been applied. Join me after the break as we cover the lesser known ways to put x-ray technology to work.

If you’ve been to a few hacker camps then you’re aware they are not the products of giant corporate entities but volunteer run community groups. You may even have volunteered yourself, and done all sorts of interesting tasks that go towards the running of the camp. But few of you will have been on the orga team of a camp, the people who put in the hard work of making it happen from start to finish. Julius ter Pelkwijk has, and at the 2018 Electromagnetic Field camp in the UK he gave us an insight into the experience.

Of course, Julius isn’t a member of the EMF orga, instead the camp that gave him the experience was last year’s SHA2017 in the Netherlands. This was over twice the size of EMF 2018, on the Dutch polder at Scoutinglandgoed Zeewolde, a scout camp in a forest next to a dyke, and while from our perspective it was a huge success, it was fascinating to pull back the curtain and hear from the other side of the event.

A large hacker camp attracts attendees from all over the world, and at the recent Electromagnetic Field in the UK there were certainly plenty of international visitors. Probably one of those with the longest journey was [Sarah Spencer] from Australia, and she deserves our admiration not just for her work but also for devoting much of her meagre luggage space to the installation she’d brought over for the event. In the lounge tent you could find the Knitted Universe, a map of the night sky with light-up Neopixel constellations covering an entire wall, and among the talks you could find her in-depth description of how she created it by hacking a 1980s Brother knitting machine into a network printer.

She starts with a potted history of knitting machine hacking, leading to the use of an emulated floppy drive replacing the mechanical item used to store scanned designs on the original hardware. She took an existing hack for a 16-bit Brother knitting machine and re-wrote it for her later 32-bit model, and then created a web interface for it called Octoknit which runs upon a Raspberry Pi. We’re then taken through the operation of a knitting machine and her further adventures in reverse engineering the file format. She ends up with a dithered 4-colour image, but there remains a problem. On the Brother, colour changes are performed by pressing a button, so something to automate the process was required. This task was taken on by her husband, who created an Arduino-driven mechanical button-presser in what had become a team effort. With this in place her only manual task became a periodic adjustment of the weight that preserves the tension in the finished knit.

Finally she moves on to the Knitted Universe itself, which at that point had become something of a viral sensation. Those of us who have created hacker camp installations will appreciate the volume of work that went into the piece, and she truly deserves the applause at the end of the talk. Watch it below the break, it’s a fascinating half-hour.

There is an air of excitement among the hackerspaces of Europe, because this month is hacker camp season. In Denmark they have Bornhack beginning on Thursday, in Italy IHC was held earlier in the month, while here in the UK we are looking forward to Electromagnetic Field. We’re excited be at Eastnor Castle for Electromagnetic Field at the cusp of August and September for several days under canvas surrounded by our community’s best and brightest work. We’ll even have a Hackaday Readers’ Village this year!

If you’ve never been to a hacker camp before, this is one that’s not to be missed. Technically this is camping, but where every structure from the smallest tent upwards has mains power and gigabit Ethernet. It’s the equivalent of a music festival if you replace the music with technology and other cool stuff from our world. There are talks on a huge variety of fascinating subjects, the chance to see up close some of the things you’ll have read about here on Hackaday, and best of all, a significant proportion of Europe’s hackerspace communities all together in one place. They are a uniquely stimulating and exciting environment.

Sometimes the world of tech conference presentations can seem impossibly opaque, a place in which there appears to be an untouchable upper echelon of the same speakers who pop up at conference after conference. Mere mortals can never aspire to join them and are destined to forever lurk in the shadows, their killer talk undelivered.

Thankfully, our community is not like that. There is a rich tradition of events having open calls for participation, and the latest we’d like to bring to your attention comes from the British EMF Camp, to be held at the end of August. EMF, (standing for ElectroMagnetic Field) is a 3-day festival that bills itself as “for those with an inquisitive mind or an interest in making things“. In their call for participation, they are seeking installations and performances as well as talks and workshops, and it’s worth saying given the very quick uptake of their early ticket sales, that a couple of tickets will be reserved for purchase by each person with proposals that are accepted.

EMF Camp like other hacker camps is an extraordinary coming together of people from all conceivable backgrounds and interest groups to share a field for three days. It doesn’t matter how experienced you are, what the subject is that you would like to present, or what installation or workshop you would like to bring, there will be a section of the EMF audience who would be very interested to see it. They list a few previous topics, from genetic modification to electronics, blacksmithing to high-energy physics, reverse engineering to lock picking, computer security to crocheting, and quadcopters to brewing. Assuming that certain submissions are accepted, you may also see a Hackaday scribe delivering a talk.